The present invention relates to a solenoid-operated valve and, more particularly, to a bi-directional piloted solenoid-operated valve which utilizes fluid pressure to provide pressure-assisted scaling and pressure-assisted actuation to the main sealing disc in both flow directions.
Pilot-operated valves which provide pressure-assisted sealing/actuation of the main sealing disc in a single flow direction are known. For example, U.S. Pat. Nos. 4,387,878, 4,082,116 and 3,994,318 disclose pilot-operated valves which utilize the inlet fluid pressure to provide both pressure-assisted sealing and pressure-assisted actuation to the main sealing disc. These pilot-operated valves, however, are configured to provide such pressure-assisted sealing/actuation in a single flow direction only. That is, the inlet port of the valve must always be connected to the higher pressure source. Stated differently, the known prior art valves are incapable of providing the mentioned pressure-assisted sealing/actuation if the flow of fluid is reversed, i.e., if the higher pressure fluid is directed into the outlet port of the valve.
As mentioned, known pilot-operated valves utilize the inlet fluid pressure to provide both pressure-assisted sealing and pressure-assisted actuation to the main sealing disc. This is particularly desirable in larger valves, and those valves used in higher pressure environments. It will be appreciated that larger valves (particularly in higher pressure environments) typically require a large force to move the main sealing disc against the pressurized fluid, thus necessitating the use of a large actuating mechanism and/or requiring a large draw of current if actuated directly by a solenoid coil. In contrast, valves including pilot valves can utilize smaller actuating mechanisms and/or draw significantly less current during operation.
It will be recognized that applications exist wherein the direction of flow of the fluid into the valve may be reversed, that is, either the inlet side or outlet side of the valve may be supplied with higher pressure fluid. One such application involves the control/distribution of fuel on an aircraft carrier. Obviously, prior art valves which provide pressure-assisted sealing/actuation in a single flow direction are unsatisfactory in such an environment.
Moreover, other factors including reliability, protection against leakage and non-electrical visual confirmation of the valve position are desirable in many valve applications, and are particularly desirable in maritime environments such as use on an aircraft carrier.
There is therefore a need in the art for a bi-directional piloted solenoid-operated valve which utilizes fluid pressure to provide pressure-assisted sealing and pressure-assisted actuation to the main sealing disc in both flow directions. Preferably, this same valve should also provide improved reliability, protection against leakage and non-electric visual confirmation of the valve position.
The present invention, which addresses the needs of the prior art, provides a bi-directional piloted solenoid-operated valve. The valve includes a valve housing, the housing having a first port and a second port. The valve further includes a main disc positioned in the valve housing and selectively movable between an open position and a closed position. The main disc defines a fluid chamber within the valve housing and includes first and second passages extending therethrough and communicating with the fluid chamber. The first passage extends between the fluid chamber and a first flow-diverting mechanism and the second passage extends between the fluid chamber and a second flow-diverting mechanism. The second passage has a greater cross-sectional area than the first passage. The valve further includes a pilot disc cooperating with the second passage and movable between a first position wherein fluid flow is interrupted between the fluid chamber and the second flow-diverting device and a second position wherein fluid flow is established between the fluid chamber and the second flow-diverting device. The first flow-diverting mechanism is selectively movable between the first position wherein a fluid connection is provided between the first port and the fluid chamber and a second position wherein a fluid connection is provided between the second port and the fluid chamber. The second flow-diverting device is selectively movable between a first position wherein a fluid connection is provided between the second port and the fluid chamber and a second position wherein a fluid connection is provided between the first port and the fluid chamber whereupon the application of pressurized fluid to either of the ports provides both pressure-assisted sealing and pressure-assisted actuation of the main disc.
In one preferred embodiment, the valve includes an actuating mechanism for moving the pilot disc between its first position and its second position. The actuating mechanism is preferably an electromagnetic solenoid assembly, which is also coupled to the main disc to selectively move the main disc between the opened and closed positions.
In another preferred embodiment, the valve includes a position indicator for providing visual confirmation of the position of the main disc. The position indicator includes a pivotally mounted lever rotatable between a first position indicating that the main disc is in the closed position and a second position indicating that the main disc is in the open position. Both the main disc and the lever are provided with cooperating magnets which cause the lever to rotate between its first and second positions as the main disc moves between the closed and open positions.
As a result, the present invention provides a bi-directional piloted solenoid-operated valve which utilizes fluid pressure to provide pressure-assisted sealing and pressure-assisted actuation to the main sealing disc in both flow directions. This same valve provides improved reliability, protection against leakage and non-electric visual confirmation of the valve position.